OBJECTIVE: To investigate acute toxicity of piperphentonamine hydrochloride (PPTA) in rats and Beagle dogs, and to calculate maximum dosage and evaluate its safety. METHODS: SD rats were given relevant medicine via ig or iv, at a single dose of 50 mg/kg, every 4-6 h, for consecutive 3 times, 150 mg/kg in total; after 14 d treatment, the toxicity reaction and body weight of rats were observed in PPTA group (n=40) and solvent control group (n=20). Beagle dogs were given PPTA ivgtt, at maximal single dose of 200 mg/kg; after 14 d of treatment, Beagle dogs of PPTA group (n=4) and solvent control group (n=3) were observed in respects of general physiological index, body weight, body temperature, ECG index, blood pressure, plasma electrolyte, urine, ophthalmology and pathological index, etc. RESULTS: There was no obvious abnormality in rats after ig administration of PPTA. One-off action instability occurred after iv within minutes; no abnormality was found for 14 days; the increase of body weight of rats in treatment groups was normal. Transient conjunctival congestion, nausea and vomiting, salivation, mild edema eyelids and rear limb weakness were observed in Beagle dogs during dosing; only one Beagle dog suffered from hematuria caused by hemorrhage of bladder. 14 d after medication, there was no statistical significance in body weight and temperature of Beagle dogs between treatment groups and solvent control group (P>0.05). No abnormal changes due to drug toxicity reaction were observed. CONCLUSIONS: LD50 values of PPTA in rats via ig and iv are over 150 mg/kg. Beagle dogs did not died at the single dose of 200 mg/kg PPTA, ivgtt. The abnormal signs of animals may be the side effects of PPTA. The main toxic reaction of PPTA may be hemorrhage of bladder and other.